The current display device of a flat display panel such as Liquid Crystal Display (LCD), Organic Light-Emitting Diode (OLED) display, or Plasma Display Panel (PDP) are mainly used in notebook computers, portable electronic equipment and so on. With the increasing demand for large screen in portable electronic devices, the flat display panel having large-screen display units and able to be connected with is being developed and commercialized. In particular, the foldable display device draws more attention due to its portability, with the advantage of the bendable or foldable flexible display panels.
The inventor of the present application has found in the long research that the flexible OLED display panel is light-weight, non-friable, foldable, and so on, and is often adopted as a flexible screen for the display device. However, after the foldable display panel is folded, the stress is over concentrated at the folding area to cause breakage or wrinkle.